Segmental type toggle lock



R. A. CHACE SEGMENTAL TYPE TOGGLE LOCK Aug. 29, 1961 2 Sheets-Sheet 1Filed Feb. 8, 1960 SMQ IHY

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SEGMENTAL TYPE TOGGLE Loox Filed Feb. 8, 1960 2 sheets-sheet 2 gg@ jINVENTOR. PMA/AED A (ff/,4 of

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A 7702/104? Vj' United States 2,997,985 SEGMENIIAL TYPE TOGGLE L'OCKRichard A. Chace, Bellevue, Wash., assignor, by mesne assignments, toClemco Aero Products, Inc., Gardena, Calif., a corporation of DelawareFiled Feb. 8, 1960, Ser. No. 7,296 7 Claims. (Cl. -121--40) The present`device is of the same general nature yas that disclosed in Patent No.2,744,501, issued to myself and George C. Newell, Ir., and in thecompanion patent to E. H. Bakke, No. 2,764,132, and in that it pertainsto a toggle lock employing dogs of the segmental type shown in the Bakkepatent, it more nearly resembles the latter. However, it is not materialWhether the locking dogs and their actuating means be singular orplural, whereby to lock in one or -in two positions, whether they bemounted in a piston which is reciprocable Within a cylinder as in theBakke patent, or in the cylinder for engagement with the piston, nor isit material whether the release of the lock and relative movement of thepiston and cylinder or equivalent elements =be accomplishedhydraulically or otherwise. As to equivalent elements, the Vlock isapplicable to -any two relatively reciprocable elements, whether formedas a piston and cylinder, or otherwise.

The Bakke segmental form of the lock has advantages over a narrower formof lock in that the locking and releasing pressures are distributed overrelatively wide areas and, therefore, are not concentrated to produceexcessive and concentrated wear at any one particular point or limitedarea. The Bakke construction in use was found, however, to be subject tocertain disadvantages. Projection of the segmental locking dogs intolocking position was etected by the reaction of a double-beveledactuator upon complemental bevels 4at the opposite ends of the segments.These actuator-s would, in some instances, fail to project equally orsimultaneously, which would result in cooking of the locking segments,or their displacement circumferentially, and possible failure to engageor to disengage properly. I-t was discovered after such troubles haddeveloped, that it was especially necessary for locking dogs of thissegmental type to be so guided in the member which supports them, thatthey may move only radially, and in no sense circumterentially, norcock. The present invention relates to a construction wherein suchsegmental locking dogs are so guided, and in that manner are preventedfrom cocking or sticking, and will, in consequence, continue to workperfectly for lan indeiinite period of ltime.

The invention is shown in the accompanying drawings in tworepresentative forms, the dierences between which will appear shortly.

FIGURE 1 is a longitudinal sectional view through a hydraulic jack,sunt, or the like, shown with parts in a locked position at one end ofthe relative travel of the two members, and incorporating the presentinvention.

FIGURE 2 is, in general, a transverse sectional view at the planeindicated by the line 2 2 in FIGURE l.

FIGURE 3 is an exploded isometric and part-sectional view of themechanism employed in the form of the device shown in FIGURES 1 and 2.

FIGURE 4 is a transverse sectional view, corresponding generally toFIGURE 2, -and showing a modified form of guiding device for thesegmental locking dogs, and FIGURE 5 is an axial sectional view of oneend only of the same, taken substantially at the plane indicated by theline 5 5 in FIGURE 4.

FIGURE 6 is a transverse sectional view directly through the guidingelement of this form of the device.

The present invention is, in fact, applicable to any pair of relativelyreciprocble elements which must be locked isaiasi Patented Aug. 29, i961ice together in at least one position, and will be shown and describedin conjunction with a piston and cylinder constituting the respectiveelements, and which in the embodiment shown are locked together at eachof two limits of their reciprocative movement. Relative movement betweensuch positions is elected by the application of hydraulic pressure orthe like behind the one end or the other of the piston.

The cylinder is indicated at 11, having a bore 10 and the ends beingclosed by end caps 11 and 12, the whole being held assembled by meanssuch as the bolts 13 joining the end caps. One of the end caps isaxially bored for sliding of a piston rod 20 in and out, this beingconnected interiorly of Ithe ycylinder 1 to a piston 2 which is fittedand reciprocable within the bore 10. The cylinder reacts from one of twomembers (not shown) which are to be moved apart or together, and thepiston rod reacts from the other such member. Fluid passages foradmission of pressure lluid to the respective ends of the cylinder, andfor venting of the opposite end to a low pressure region, are indicatedat 13a and 13b.

Locking dogs 3a and 3b are supported in and adjacent the respective endsor faces of the piston 2, in circumferential grooves 23, for radialprojective and retractive movement. Each such locking ldog at itsradially outer or tip end is of segmental form, as best seen in FIGURE2. In the form shown such dogs when retracted constitute a substantially360 ring, but when projected as shown in FIGURE 2, are somewhatseparated at their ends. It is this separation, which in the absence ofthe guidance provided according to this invention, would permitcircumferential or endwise movement, or cooking with relation to aradius, and it is such irregular movement of the dogs, often induced bythe projecting means employed, that has in past forms caused trouble.

Each dog 3a or 3b is beveled with relation to the direc- -tion ofreciprocation of the piston 2, at its tip and along one face, asindicated -at 30 in FIGURES l and 3. When the dogs are projected andlocked in projected position these beveled'suriaces will engagecomplementally beveled surfaces 14a and 14b outwardly of the respectiveends yof the cylinder bore 10, `and so will lock the piston wherein thedogs are mounted, with relation to the cylinder wherein the pistonslides. The bevels are of such slope with relation to the direction ofreciprocation that pressure on the piston in opposition to the lockaiforded by the shoulder and fthe beveled dog engaging it, will tend tourge the dog radially inwardly into its retracted position unless it islocked and lheld positively projected.

The dog projecting and locking means is similar to that disclosed in theBakke patent. It includes toggle links y4 the outer end of each whereofis operatively engaged with its respective dog 3a or 3b, and each togglelink is fulcrumed at its inner end upon a `fulcrum member S a skirt 50whereof is guided within a bore 20a or 20b disposed axially within thepiston 2. A servo piston 53 formed on the fulcrum member 5 slidesaxially within a servo cylinder 25a or 25b in the piston 2. Each servocylinder is vented at 22 to lthe opposite face of the piston 2. Springmeans 51 urge the ulc-rum members 5 axially outwardly or away lfrom thecenter of the piston 2. When the dogs are retracted, as are the dogs 3ain FIGURE 1, the toggle links 4 yare not in alignment with the directionof the dogs movements, and the spring pressure of the spring 51 cannotmove the dogs outwardly, for their outer end or .tip rides within thebore 10. However, when the dogs are disposed axially outwardly beyondthe beveled shoulders 14a or 14h, as are the dogs 3b at the left inFIGURE l, the spring pressure 51 acts through the fulcrum member 5 tomove the toggle lin-ks 4 into alignment with the dogs and forces thedogs, 312 in th s instance, outwardly beyond the bore and intoengagement with the shoulder 14b. The toggle links `4, stopped byabutting the transverse face 54 of fulcrurn member 5 remain in alignmentand engaged with the dogs, thus to hold the dogs in locking position.

To etfect movement of the piston 2 within the cylinder 1 from the lockedposition at the left in FIGURE 1 to the right and to a second lockedposition at the opposite end, it is only necessary to apply pressure atthe port 13b, venting the opposite end of the. cylinder through port13a; Application of pressure at 13b applies pressure to the exposed endface 54 of the :fulcrum member 5, which urges its servo piston 53 withinthe servo cylinder to the right, in opposition to spring 51, the rightend of servo cylinder a being vented to the opposite end of the bore 10by means of the vent 22. The same hydrauhc pressure admitted at 13b isalso applied to thev left end of the piston 2, and immediately uponmovement of the fulcrum member S to the right, the pressure upon theleft end of the piston 2 urges the dogs-3b, is still projected, againstthe bevel of their shoulders 14b, and causes inward retractive movementof the dogs, so that now the piston, being free of any lock, is causedto traverse the bore 1l) to the right. Eventually the piston will moveto the extreme right end of the cylinder 1 and the compression on theright hand spring 51, assisted if need be by hydraulic pressure admittedbehind the servo piston 5 through the vent passage 22, will now causerightward movement of the right fulcrum member 5, and the links 4 atthis end will move the dogs 3a outwardly, and the links will move intoalignment with them. Thereby the piston 2 will be locked by engagementof the dogs 3a with the shoulder 14a, which lock will be'rnaintained,despite cessation of hydraulic pressure, -until application of pressurethrough the port 13a to the right hand end of the cylinder.

As has been indicated above, the dogs, if permitted to move other thandirectly radially, may not engage or disengage properly and evenly.Accordingly, a guidance element 6 s(ee FIGURE 3) is provided, fittedupon the fulcrum member 5 by mens such as the stem 52 projecting from anend thereof and passing through an aperture 60 in the element I6, andsecured in place by a nut 55. This guidance element 6 is formed withplanar guide faces 61 which closely receive and guide the planar faces31 of a radial stern 32 of each dog member 3a or 3b. The stems 32 alsopass through -radial bores 26 in the piston 2, leading to the groove 23.Due to the close tit of the faces 31- between the faces 61, the dogs arepermitted only radial movement. They cannot move circumferentially, norcan they rotate to cock or stick. As a result, the dog segments at anygiven end -move precisely radially into and yfrom locked position.

Similar guidance can be aiorded the locking dog members even though theymore nearly resemble or are actuated as are the dogs of the Balnkepatent. Such dogs are shown in FIGURES'4, 5 and 6, and are designated,to distinguish them, 3c.V These dogs are not directly engaged by thetoggle lever members indicated at 4c, but their ends are beveled asindicated at 33, and these beveled ends are urged outwardly by theprojective movement of a complementally beveled element 42 which engagesthe opposite ends of two adjoining segments 3c, and which is itselfurged outwardly by projective rotation of the toggle levers 4c.Similarly, upon collapse inwardly ofthe toggle levers 4c the elements 42may move inwardly, and are urged inwardly by the inward pressure on thedogs communicated through the bevels 33 to the complemental bevels ofthe elements 42. Guidance of the dogs 3c in this instance is aiorded byradially directed pins 34 supported in the piston 2 and engaging in acomplemental groove 35 in the dog 3c (see FIGURE 6).

I claim as my invention:

l. In combination with a pair of members guided for relativereciprocative movement, means to lock said members against relativereciprocation in a given position, said means including acircumferentially directed shoulder on one such member beveled relativeto the direction of reciprocation,` a segmental locking dog carried bythe other such member for radial movement and beveled complementally tosaid shoulder for looking engagement therewith or disengagementtherefrom, toggle link means separate from said locking dog, movableinto radial alignment with said locking dog and from such alignment, andoperatively engaged therewith to eiect the locking dogs radial movementor into locking engagement to allow its opposite movement, and meansengaging said locking dog torestrain the same against movement otherthan direct radial movement.

2. In combination with a cylinder, a piston slidably nitted therein forreciprocation toand from a given locked positiom means to effect suchrelative reciprocative movement between the piston and its cylinder, alocking device including a shoulder on one of the relativelyreciprocable members beveled relative to the direction of reciprocation,a plurality of part-segmental locking dogs supported in the other suchmember and beveledv for interengagement with the beveled shoulder, meansguiding each such dog for Iradial movement only in its mounting member,for engagement with or disengagement from said shoulder, toggle linksseparate from the dogs and rockably mounted in the dog-mounting member,and each bearing at one end upon the corresponding dog, a fulcrum membermounted in the same member for axial lreci-procative movement, andoperatively engaged with the other end of said links to shift them intoalignment with said dogs and so to move the latter into position whereinthey engage the shoulder, or to shift from such alignment for movementof the dogs from shoulderengaging position; spring means urging thetoggle links towards such aligned position, and means to shift saidfulcrum member at will in opposition to said spring means into positionfor movement of the locking dogs from shoulder-engaging position byreaction between the beveled surfaces.

3. The combination of claim 2, wherein the dog-guiding means include aradially directed non-circular stem projecting from a midpoint of eachsegmental dog, and a complementally shaped radial guide for the stemformed in thedog-mounting member.

4. The combination of claim 2, wherein the operative engagement betweenthe dogs and the toggle links include actuators oppositely beveledV attheir tips, the segmental dogs being complementally beveled at theirends for projective movement by movement of the actuators in one senseor retractive movement by movement of the actuators in the oppositesense, and wherein the dog-guiding means includes a radially directedkey interengagedY between each segment and its supporting member.

5. In combination with a cylinder, a piston slidably iitted -therein forreciprocation to and Vfrom a givenV locked position, means to eifectsuch relative reciprocative movement between the piston and itscylinder, a'locking device -including a shoulder within the cylinderbeveled relativer to the direction of reciprocation, a plurality ofpart-segmental locking dogs'supported in the' piston and beveledcomplementally to ande for locking engagement with the beveled shoulder,Ameans Vguiding eachv dog in its pistonfor radial projective andVretractive movement only, togglelinks rockably mountedin the piston, andseparate from but bearing at their outer ends upon therespective dogs, afulcrum member axially reciprocative Yin the piston and operativelyengaged withthe inner ends of said toggle links to shift them outwardlyandjinto alignment with said dogs and so to projectA the dogs intolocked shoulder-engaging,position, or inwardly for retraction of thedogs, spring meansvurging Vthe toggle links towards such projectedposition, and means to shift said fulcrum member at Will in oppositionto said spring means into position for' retractive movement of the dogsby reaction between the beveled surfaces.

6. The combination of claim 5, including means for admission of pressureuid to and its relief from the ref spective ends of the cylinder,thereby to effect reciprocative movement of the piston within thecylinder, and a servo cylinder in the piston proper and a servo pistonmounting the fulcrum member and exposed to the pressure fluid admittedto the cylinder proper, and vented to the opposite end thereof,constituting the means to shift 10 the fulcrum member.

7. 'Ihe combination of claim 6, wherein the cylinder is bevel-shoulderedat each limit of the pistons travel,

and including two sets of dogs, toggle links, and fuicr'ur members atthe respective faces of the piston proper, and a servo piston and servocylinder arranged at each piston face for shifting the fulcrum member atthe corresponding face.

References Cited in the tile of this patent UNITED STATES PATENTS1,842,776 Bogoslowsky J an. 26, 1932 2,744,501 Chace et al May 8, 19562,764,132 Bakke Sept. 25, 1956 UNITED STATS- PATENT` OFFICE CERTIFICATE0F CORRECTION Pax-,ent No. 2997985 August 2% 1961 RichardA. Chace It is`hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column lq lines l2 and 13x for ."or ntfo locking engagement 13o allowread m into' locking engagement, or Lo Signed and sealed this 13th dayof March 1962.

(SEAL) Attest:

ERNEST W. SWDER Attesting Officer DAVID L. LADD Commissioner of Patents

